Opencv Learning (2) -- Basic Data Structure

Basic Data Structure of opencv

Cvpoint: the point in the image.

Cvpoint2d32f: point in two-dimensional space

Cvpoint3d32f: Point in 3D space

These are struct and are not classes in the C ++ language. Therefore, their constructor is a simple inline function.

 1 typedef struct CvPoint 2 { 3     int x; 4     int y; 5 } 6 CvPoint; 7  8  9 CV_INLINE  CvPoint  cvPoint( int x, int y )10 {11     CvPoint p;12 13     p.x = x;14     p.y = y;15 16     return p;17 }

Cv_inline is a macro definition:

1 define CV_INLINE inline

Cvsize: indicates the image size.

Cvsize2d32f: float data indicates the image size

 1 typedef struct CvSize 2 { 3     int width; 4     int height; 5 } 6 CvSize; 7  8 CV_INLINE  CvSize  cvSize( int width, int height ) 9 {10     CvSize s;11 12     s.width = width;13     s.height = height;14 15     return s;16 }

Cvrect indicates part of the image

 1 typedef struct CvRect 2 { 3     int x; 4     int y; 5     int width; 6     int height; 7 } 8 CvRect; 9 10 CV_INLINE  CvRect  cvRect( int x, int y, int width, int height )11 {12     CvRect r;13 14     r.x = x;15     r.y = y;16     r.width = width;17     r.height = height;18 19     return r;20 }

Cvscalar contains four floating point Members, which can be used to represent B, G, R, and Alpha. It has three constructors with specific definitions:

Typedef struct cvscalar
{
Double Val [4];
}
Cvscalar;

// Specify at least one parameter. If the last three parameters do not exist, the default value is 0.
Cv_inline cvscalar (double val0, double val1 cv_default (0 ),
Double val2 cv_default (0), double val3 cv_default (0 ))
{
Cvscalar scalar;
Scalar. Val [0] = val0; scalar. Val [1] = val1;
Scalar. Val [2] = val2; scalar. Val [3] = val3;
Return scalar;
}

// Only assign values to the first parameter, followed by 0
Cv_inline cvscalar cvrealscalar (double val0)
{
Cvscalar scalar;
Scalar. Val [0] = val0;
Scalar. Val [1] = scalar. Val [2] = scalar. Val [3] = 0;
Return scalar;
}

// Assign all four parameters to the input parameter
Cv_inline cvscalar cvscalarall (double val0123)
{
Cvscalar scalar;
Scalar. Val [0] = val0123;
Scalar. Val [1] = val0123;
Scalar. Val [2] = val0123;
Scalar. Val [3] = val0123;
Return scalar;
}

Relationship between cvarr, cvmat, and iplimage

The derivation is: cvarr --> cvmat --> iplimage. When cvarr is used as a function parameter, cvmat is used internally, regardless of whether cvmat or iplimage is passed in.